Field of the Invention
Priorities are claimed on Japanese Patent Application No. 2014-243132, filed Dec. 1, 2014, and Japanese Patent Application No. 2015-139847, filed Jul. 13, 2015, the contents of which are incorporated herein by reference.
Embodiments of the present invention relate to laser gas analyzers.
Related Art
A laser gas analyzer is a device which irradiates a laser light onto a gas to be measured and measures components contained in a gas to be measured and the concentration, etc., thereof based on the absorption spectrum of a laser light which transmits the gas to be measured. This laser gas analyzer is configured to generally include a light emitter which emits a laser light for irradiating onto the gas to be measured and a light receiver which receives a laser light which transmitted the gas to be measured. Such a laser gas analyzer is often installed such that the light emitter and the light receiver face each other with a smoke duct placed therebetween. The smoke duct is a duct through which the gas to be measured is guided.
An optical axis adjustment mechanism which is a mechanism for an optical axis adjustment is provided in the light emitter and the light receiver of the laser gas analyzer, and the optical axis adjustment is performed between the light emitter and the light receiver at the time of periodic or aperiodic maintenance as well as at the time of installation of the laser gas analyzer. This is because, when there is an offset between an optical axis of the light emitter and an optical axis of the light receiver, a light amount of the laser light received in the light receiver decreases to cause the measurement accuracy to decrease.
The optical axis adjustment between the light emitter and the light receiver of the laser gas analyzer is generally performed in accordance with the following procedures:
(1) The optical axis of the light emitter is adjusted such that the transmittance of the laser light is maximal;
(2) The optical axis of the light receiver is adjusted such that the transmittance of the laser light is maximal; and
(3) The optical axis of the light emitter is adjusted such that the transmittance of the laser light is maximal.
One example of a laser gas analyzer which makes it possible to adjust an optical axis over a wide range is disclosed in JP2010-096631A.
In a related-art laser gas analyzer, a calculation device which calculates components included in a gas to be measured and the concentration, etc., thereof; and calculated results or measured results of the calculation device. Therefore, the optical axis adjustment of the light emitter of the above-described procedures (1) and (3) can be performed by a worker himself while he checks the display content or the transmittance of the laser light of the display. However, it is difficult to perform the optical axis adjustment of the light receiver that is described above in the procedure (2) by the worker himself because the worker may not visually check the transmittance of the laser light.
Thus, presently, a worker who performs the optical axis adjustment of the light emitter and a worker who performs the optical axis adjustment of the light receiver work as a pair and, when the optical axis adjustment of the light receiver is performed, the optical axis adjustment of the light receiver is performed while conveying the display content of the display using communications devices such a transceiver, a mobile telephone, a PHS or a personal handyphone system, etc. In this way, presently the efficiency is poor due to the fact that at least two workers are needed to perform the optical axis adjustment between the light emitter and the light receiver of the laser gas analyzer.
Moreover, when the diameter of the smoke duct along which the light emitter and the light receiver of the laser gas analyzer reaches several tens of meters, the transmittance of the laser light decreases significantly with a slight offset in the optical axis. In such a case, although it is not impossible to perform the optical axis adjustment of the light receiver with a method of performing the optical axis adjustment while conveying the content of the display using the communications devices, the task efficiency is substantially reduced relative to a method of performing the optical axis adjustment while the worker visually checks the content of the display.